Spur gear pump



Patented Dec. 2, 1930 UNITED STATES PATENT OFFICE IB'VEN H. WILSiEY, OF CHICAGO, ILLINOIS, 'ASSIGNOR TO 'J'AMES B. TUTHILL, OF CHICAGO,

i us stun. GEAR rm Application filed December 29, 1926. Serial No. 157,673.

The present invention relates to improvenients in spur gear pumps, particularly such as are adapted for use as automobile engine oil pumps. 4. The primary objects of the invention are to provide a novel spur gear pump which has a highefiiciency and a long life; which is adapted to handleliquids of different viscosities with equal efliciency; which will per- -mit grit, dirt and other foreign particles to pass through without causing excessive wear; which in one manner of use will per 1 mit excessive pressures at the discharge port to be automatically relieved, thereby obviating the necessity of relief valves; and wh ch is extremely simple and inexpensive 1n construction.

Another object resides in the provision in a novel spur gear pump of movable lands which are separate from the pump housing; which are self-seating'and follow the contour of the gears; and which are highly re- 1 sista'nt to wear.

Ancillary objects and advantages will become apparent as the description proceeds.

In the accompanying drawings, Figure 1 is a longitudinal sectional view taken along,

the invention to the construction disclosed,

but aim to cover all modifications'and alternative constructions falling within the spirit and scope of the invention as expressed 1n the appended claims.

Referring to the preferred embodlment 1llustrated in the drawings, the pum comprises an elongated hollow casing 4, t e ends of which are closed by end plates 5 and 6,secured thereto by any suitable means, such as bolts 7. The end plate 6 preferably isformed integral with-a suitable support 8. Formed in the elongated sides of the cas1n g 4 and directly opposite'each other are an inlet port 9 and a discharge port 10, said ports, being adapted to be connected in any suitable fluid line-(not shown).

-Mounted respectively on shafts 11 and 12' in opposite sides of the casing 4are two gear '5 members 13 and 14. The gear members are preferably spur gears, and meshat the center of the casing 4. The shafts 11 and 12 are journaled in the end plate 6, and the shaft 11 y is adapted to be driven by any suitable power 0 means (not shown).

A pair of opposed lands 15 and 16 are rovided in the opposite short side walls 0 the casing 4, and engage the outer remote sides of the gears 13 and 14 in a plane midway between the ports 9 and 10. In Fig.- 1, the

. lands 15 and 16 consist of blocks which are .slidable in guideways 17 and 18 respectively,

formed in the walls of the casing 4. The inner end surfaces'of the lands 15 and 16 are shaped to conform to the curvature of the gears -13 and 14, and are pressed yieldingly into engagement therewith by coil springs 19 and 20, respectively. Each of these springs is disposed in a bore 21 in the back of one of 76 the land blocks, and abuts at its'outer end agamst the end of the associated guideway. The inner ends of the guideways 17 and 18 are vented respectively through passages 22 Preferably, I 30 sides of the and 23 to the inlet chamber. these passages are formed in the lands 15 and 16. 1

In Fig. 2, the lands 15 and 16 consist of curved plates pivoted in the walls of the casing 4. Each of the lands 15 and 16 is=g5 formed at one end with a cylindrical bearing 24 rotatably mounted in a cylindrical socket 25 in the casin 4. The backs of the lands are exposed to t e pressure in the inlet chamber. Coiled springs 26 disposed in bores 27 in the walls of the casing 4 abut against the backs of the lands, lands yieldingly in engagement with the gears 13 and 14.

In operatiomassume that the gear member 13 is driven counterclockwise. This member' will drive the gear member 14 ha clockwise direction. In moving past the lands 15 and 16, the gear members will carry'fluid fronr the inlet chamber to the discharge chamber.

and tendto hold said The movable lands and 16 are self-seating. and will find and maintain the proper film thickness for the particular liquid that is being handled. As a result, the pump will never out the natural film thickness, and hence considerable saving of power will result. As the parts wear, the movable lands cee'ds a predetermined value, it will move the lands 15 and 16 away from the gears 13 and 14, thereby resulting in an automatic pressure relief by by-passing liquid from the dischargechamber past said lands into the inlet chamber.

If rotation of the gears 13 and 14 were reversed, the port 10 would become the inlet,

and the port 9 would become the discharge,

and the backs of the lands 15 and 16 would be exposed to the discharge pressure. The sealing effect of the lands would then vary in proportion to the pressure against which the pump would be operating.

It will be evident that I have provided aj spurgear pump which. is extremely simple.

and inexpensive in construction, and in which the objects set forth in the foregoing are clearly carried out.

I claim as my invention:

1. A gear pump having, in combination, a

casing, an inlet passage in one side of said casing, a discharge pass -ge in the other side of said casing, apair of gear members mounted side by side in said casing and meshing with each other, a pair of opposed guidesaid blocks to said low pressure inlet passage, and spring means tending to press said blocks into engagement with said gears.

3. A gear pump having, in combination, a casing, a relatively low pressure inlet passage in one side of said casing, a relatively high pressure discharge passage in the other side of said casing, a pair of guideways in said casing, a pair of gear members mounted side by side in said casing and meshing with each other, a pair of lands movably mounted in said guideways and engaging the respective peripheries of said gear members, the fronts of said lands being partially exposed to the pressure in the discharge passage, the backs of said landsbeing exposed to the pressure in said inlet passage, and spring means tending to press said lands into engagement with said gear members.

In testimony whereof, I have hereunto aflixed my signature.

IRVEN H. WILSEY.

ways formed in said casing, a pair of lands 'slidablylmounted in said guideways for engagingthe respective peripheries of said gear members, vent passages formed in the sides of said lands for venting the ends of said guideways back of said lands to said inlet passage, and spring means tending to press said lands into engagement with said gear mem bers. f

2. A spur gear pump having, in combination, an elongated casing, a relatively low pressure inlet passage in one side of said casing, a relatively high pressure discharge passage in the other side of said casing, a pair of spur gears mounted in said casing and meshing with each other, a pair of rectangular opposed guideways formed in said casing in ends thereof, a pair of rectangular blocks constituting lands snugly and slidably mounted in said guideways for engaging the respective peripheries of said gears, vent passages formed in the sides of said blocks for venting the ends of said guideways back of 

